When your car's Check Engine light comes on, it's usually accompanied by a sinking feeling in the pit of your stomach. The light could mean a costly problem, like a bad catalytic converter, or it could be something minor, like a loose gas cap.
If you experience any bleeding period after this 20 days, it will probably be the real period. This normally comes at about 4 to 6 weeks after the miscarriage.
The problem is, finding out when her next period will be. If her miscarriage was devoid of complications, and if her cycle was previously quite regular, she can expect to have a period within a four to six week time frame, from the date of the miscarriage.